*{
    margin: 0;
    padding: 0;
}
html,body,#app{
    width: 100%;
    height: 100%;
    position: relative;
    background: url('https://wimg.588ku.com/gif320/24/07/09/78ebb646c4c14e9cbb25aa751986b38f.gif') no-repeat center;
    background-size: contain;
}
